/* pwm_mp.avr.c - PWM to be used with motor-power-avr. */ /* asserv - Position & speed motor control on AVR. {{{ * * Copyright (C) 2008 Nicolas Schodet * * APBTeam: * Web: http://apbteam.org/ * Email: team AT apbteam DOT org * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * }}} */ #include "common.h" #include "pwm_mp.avr.h" #include "pwm.h" #include "modules/spi/spi.h" #include "io.h" /** Assign PWM outputs. */ #define PWM1 pwm_left #define PWM2 pwm_right #undef PWM3 #undef PWM4 #include "pwm_config.h" /** When true, start transmission. */ uint8_t pwm_mp_go; /** Initialise communication with motor-power-avr. */ void pwm_mp_init (void) { #if PWM1or2 || PWM3or4 spi_init (SPI_IT_DISABLE | SPI_ENABLE | SPI_MSB_FIRST | SPI_MASTER | SPI_CPOL_FALLING | SPI_CPHA_SETUP | SPI_FOSC_DIV16); #endif } /** Update PWM values. */ void pwm_mp_update (void) { #if PWM1or2 || PWM3or4 uint8_t v; uint8_t cks; if (PWM1c (PWM1) || PWM2c (PWM2) || PWM3c (PWM3) || PWM4c (PWM4)) pwm_mp_go = 1; if (!pwm_mp_go) return; #endif #if PWM1or2 /* Chip enable. */ PORTB &= ~_BV (0); /* Convert to 12 bits. */ uint16_t pwm1 = PWM1c (PWM1) << 1; uint16_t pwm2 = PWM2c (PWM2) << 1; /* Send, computing checksum on the way. */ cks = 0x42; v = ((pwm1 >> 4) & 0xf0) | ((pwm2 >> 8) & 0x0f); spi_send (v); cks ^= v; v = pwm1; spi_send (v); cks ^= v; v = pwm2; spi_send (v); cks ^= v; spi_send (cks); /* Chip disable. */ PORTB |= _BV (0); #endif }